Tripping device for electric switches



Dec. 20, 1927. 1,653,195

J. D. Woon TRIPPNG DEVICE FOR ELECTRIC SWITCHES Filed Nov. 5'. 1924 2 Sheets-Sheet l Dec. 20, 1927. 1,653,195

J. D. woon TRIPPING DEVICE FOR ELECTRIC SWITCHES Filed Nov. s. 1924 sneets-sneet 2 jaefz 7o.

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Patented Dec. 2Q, 192.7.

UNITED S'lii'I'ES` PATENT OFFICE.

JOSEPH D. "WOOD, OF QUNCY, MASSACHUSETTS, ASSIGNOR, BY MESNE ASSIGNMENTS,

T CONDIT ELECTEJCAL MANUFACTURING CORPORATION, 0F BOSTON, MASSACHU- SETTS, A COREOBJATION O1? MASSACHUSETTS. i

TRIPNG :DEVItCE FOR ELECTRXC. SVJITCl-IES..

Application led November 3, 1924. Serial No. 747,479.

This' invention relates to opening devices for electric switches and has particular reference to devices adapted to open the switch upon diminution or failure oi load or potential, in the circuit controlled by the switch.

Devices of the type above set Jforth usually comprise a. solenoid having an armature adapted normally to be held in raised position and to be released and drop and thereby effect the opening of the switch when the current traversing the solenoid becomes diminished to such a point that the solenoid is unable to sustain the weight ot the armature. The weight ot the armature usually is depended upon to actuate the opening oit the switch and, ordinarily7 the armaturev is caused to act directly upon the locking device of the switch. For many reasons it is desirable to have an armature of light weight, as, tor instance, in order that the device may operate within rather close upper and lower limits of energization ot' the solenoid. i light weight armature, however, ordinarily is not heavy enough by its own weight to actuate the locking device ot theswitch and, it a long extent ot travel ot the armature is permitted in order to strike a hammer blow upon the switch locking device, it is diiiicult to effect the operation of the apparatus within its desired close limits.

Consequently, it is an object of this invention to provide device of the type described with a source oi" power adapted to eil'ect the opening ot the switch and so arranged that the armature need have only the relatively small weight required to controlthe release of the source of power. f

A further object is generally to improver the construction and. operation ot tripping devices :tor electric switches.

Fig. 1 is a plan view ot a. switch-tripping device embodying the invention.

Fig; 2 is a vertical sectional elevation along lines 2-2 of Fig.` 1.

Fig. 3 is a plan section along lines 3-3 of Fig. 2.

Fig. e is a side elevation.

Fig. 5 is a perspective detail of the operating toggle of the energy storing device.

That embodiment oi' my invention herein illustrated comprises a casing composed ot an upper section 1() and a lower section 12 secured vrrgnnovably tege `her by suitable means as screws 1e. Both sections preferably are i'ormedo'l' iron or some other suitable magnetic material. 'lhe'upper casingsection A1() is more or less cylindrical in form and is provided with the internal recess 16 adapted to contain a solenoid 18. Said solenoid 18 is termed upon a vertically disposed tube 2O and a core piece 22 is carried bythe casing and fits within the upper end of said tube. A lateral opening 24E is formed through the side wall ol' said casing 10 at the lower end thereof to provide means Aiter the passage of the solenoid leads therethrough. A guard wall 26 may extend laterally from said casing and bedisposed to surround said opening 24:.

The lower casing-section 12 is formed with a circular recess 28 which is adapted to conform and be complemental with the recessy 16 and form a partial enclosure for the solenoid 18. yl`helower and solenoidsupporting wall 30 ot said recess is formed with an aperture 32 therein which is disposed co-airial with the solenoid tube 20 and van armature or core 34 is treely disposed within said solenoid tube 2O and is adapted normally to be supported in raised position, as illustrated in Fig. 2, when the solenoid winding is normally energized. V'Vhen the solenoid winding becomes de-energized or in sufficiently energized said armature 32 is adapted to tall downwardly in the tube 20, thereby to actuate the tripping device ot the switch.

The source ot power for tripping the switch is contained in a lower compartment 36 et the lower casingfsection 12. Said source yof power includes an energy-storing device comprising a tensile spring 38, which spring is adapted to have ample power to operate the tripping device of the switch. Said spring is detachably connected at one end with a lug l() of the lower casing 12. The other end oli said spring is retlexed and extended through an aperture 4t2 in a lug 14, whichlug is extended laterally :trom a cranlo arm 4-6 oifa bell-crank lever. Said bell-crank lever is tired to and is adapted tov rotatel a shaft 118, which shaft is journalled in a huh of the casing and eXtendslaterally outward beyond the casing. The normal relation oit said bell-crank lever and spring is such that said spring is under tension and is disposed constantly to urge said shaft for l-OO rotation thereby to trip the switclV and, to this end, the arm 46 is restrained releasably in such a position that said spring is slightly oli the center ot the shaft i8 and is thereby disposed to rotate said bell-crank lever in a counter-clockwise direction when so pern mitted. The above construction provides a toggle con'iprisinc,v a strut-member and a resilient member, in which toggle the crankarn'i i6 forms the strut-member and the sl'iring 3S terms the resilient member I v'ilfieans are provided normally to restrain the spring and bell-crank lever in the aforesaid relation. Said means include a locking,l lever 51, which lever is disposed beneath said bell cranl; lever and is iixed to a shatt which shaft 5:2 j ournalled in the oppoite side walls of the casing l2. Said lever -i'l is extended to a suitable point beneath and in the path ot movement et the free core F-l of the solenoid and is adapted to be depressed by the weight of said core. Said bell crank lever is formed or provided with two spaced and downwardly extended arms 53 which are disposed on -oi'iposite sides of said locking?,` lever 5l. A roller 5st is disposed in therspace between said arms and is pivoted on a pin 56 passed through and secured in said arms. tiaid roller 5stis adapted nor mally to engr ze a recess 5S in said lockingr lever 5l and the aiganoement and disposition oit said roller and locking' lever 51 is such that said lever normally serves to rcain the hcllscranl'c lever from movement due to said sprin i armature dr 5l. the bell-er i, sha't't therel' i 1s .tree to rotate in a countercloclrwise direction under the in'tluence ot said spring; 38.

Yieldingr means as a tensile spring; G0 serves normally to urge said locking' lever 5l towards a position 'tor lockingJ engagement with the bell-crank lover. r:the tension of said spring', however, is adapted to be sutliciently weak to permit said locking lever to move downwardly due to the direct weight of the armature upon it.v

An actuator-member as a trip arm 62 may be fixed to the outer end o'tI said shaft 48 and is adapted to be disigiosed in tripping relation with the locking device i9 ot a switch 6l as is illustrated diagrammaticallv in Fig. el.. l

After the mechanism has once operated to trip the switch, it must be reset. For this purpose, said trippingr arm 62 is provided with a manually-engageable handle 6ft bv which the shaft and thebell-crank lever mai7 be rotated in a clockwise direction thereby to 11e-establish the stress in. or cock, 'the spring 38 and restore the mechanism in condition for further operation.

lith the device here shown. the weight of the core 34 has'merely to overcome the relatively small amount oi resistance present in removing;r the lock on the spring 38; and said spring may be provided with ample power to trip the switch without opposing undue resistance to the operation ot its lool;- ing` mechanism.

The structure may be otherwise modilied without departingjv from the spirit of the invention.

I claim:

l. An attachment for an electric switch including the combination of an enclosing casing, a normally-energized solenoid con-- tained in the upper part ot said casing and having;V a free armature normally supported in raised position, an external actuatormember carried by said casing, operating mechanism therefor disposed in the lower part ot said casing and comprising a pivoted Yarm connected with said actuator-men'iM ber. a stretched spring extended by and close to the pivot and connected with the free end o1 said arm, restraining means tor said energy-sto:ing device having,r a component disiiosed beneath and normally tree of said a1-r mature and arranged to be actuated by the weight thereof to release said energy-ster ing device tor operation, and manual rest-tw ting)` means tor said energy-storing means disposed externally of said casing.

2. A. trippingI device Yfor an electric switch ccanprisinq the combination of a pivoted arm, a latch normally arranged in holding engagement with said arm and an actuating sprin r for said ar n connected therewith a" its e end and in the latched position et said arm normally occupying a position close to but slightly to one side oi the pivot point ot said arm, said arm thus taking practically all ot the tension ot said springr and relieving; said latch ot the greater part of the spring` tension, said arm when released by said latch being;l moved about its pivot by said spring and said spring by such niovement being; `moved away troni the pivot oli said arm, aud tripping means for the latch.

3. A trippingidc'vice for an electric switch having' the combination oit a pivoted arm7 spring extended by and close to the pivot and connected with the tree end oit said arm, alatch nfunially engagingA said arm and tripping' means vtor the latch.

l. The combination ot a normally-energized solenoid having a free armature normally supported in raised position, a pivotallyenounted bell-crank lever having two angularly-related arms, a spring connected with one ot said arms and extended by and close to the pivot of said lever, a pivoted locking lever having means to engage said other arm of lsaid bell-crank lever and restrain it from rotation, said locking lever having a component disposed beneath and normally free of said armature and adapted to be depressed by the weight thereof to release said bell-crank lever for rotation, and yielding means constantly urging said lever towards locking position.

5. The combination of a normally-energized solenoid having a free armature normally supported in raised position, an actuator-device including a shaft, an actuatorarm fixed to said shaft, a bellcranlr lever also fined to said shaft, a tension spr-ing' connected with one of the arms of said bellcranlr lever and arranged constantly to urge it and said shaft for rotation, a locking lever engageable with the other arm of said bellcrankl lever to restrain it against rotation and having a component thereof extended beneath and in position to be depressed by the weight of said free armature, whereby to release said bellcrank lever for rotation, and yielding means constantly urging said locl7-` ing lever toward locking position.

6. The combination of a normally-energized solenoid having a free armature supported in raised position, an actuator-device including a shaft, an actuatonarm fixed to said shaft, a tension spring connected with one of the arms of said bell-crank lever and arranged constantly to urge it and said shaft for rotation, a locking lever engageable with the other arm of said bell-crank lever to restrain it against rotation and having a component thereof extended beneath and in position to be depressed by the weight of said free armature, wherebyy to release said bell-cranlr lever for rotation, yielding means constantly urging said locking levertoward loclring position, and manual means to rotate said bell-crank lever vagainst the action of said spring.

7. The combination of a normallyfenergized solenoid having a free armature normally supported in raised position, an actu ator-device including a shaft, an actuatore arm fixed to said shaft, a crank-arm also fixed to said shaft, a tensile spring connected with said crank-arm and arranged constantly to urge said shaft for rotation, a pair of spaced arms fixed to said shaft, a latch-roller pivotally .mounted between said arms, a locking lever disposed beneath said roller and having a recess adapted normally to receive said roller, whereby to restrain said shaft against rotation, said locking lever having a component disposed beneath said armature and adapted` to be depressed by the weight of said armature, thereby to disengage with said roller, yielding means constantly urging said locking lever toward en gaging relation with said roller, and manual means to rotate said shaft against the action of said spring, whereby to reset the device.

8. The combination of a casing having upper and lower detachable sections, a solenoid contained mainly in said upper casingsection and having a free armature normally supportedvin raised position, a shaft journalled in said lower casing-section beneath said solenoid and extended outwardly beyond the casing, an arm fined to said shaft, a crank-arm disposed within said casing and fixed to said shaft, al tensile spring connected with said arm and arranged constantly to urge said arm and shaft for rotation, and means normally t-o restrain said arm and shaft from such rotation including a second arm fixed to said shaft, a roller carried by said arm, a locking lever pivoted below said roller and located to engage therewith, whereby to restrain said shaft from rotation, said locking lever disposed beneath said armature and adapted to be depressed by the weight thereof, whereby to release said roller and permit the shaft to be rotated, and yielding means constantly urging said locking lever toward locking engagement with said roller.

9. The combination of a casing having upper and lower detachable sections,ieach provided with complemental recesses therein, a solenoid contained in said recesses, said lower casing having a solenoid-supporting wall at the bottom of its recess provided with an aperture, Va free armature adapted normally to be supported in raised position within said solenoid and drop through said aperture when said solenoid is cle-energized, a shaft journalled in and extended through said lower casing-section, an actuating-arm fixed to the extended end of said shaft, energy-storing means associated with said shaft and arranged constantly to urge said shaft for rotary movement, and restraining means for said energy-storing means having a component disposed beneath said aperture in position to be depressed by the weight of said armature, whereby to release said energy-storing means to rotate said shaft.

In testimony whereof, I have signed my name to this specification.

JOSEPH D. "WOOD 

